Drop Down Descriptions Field

I am trying to create a Mail Merge document that will allow me to input several paragraphs into an MS Word document during a Mail Merge. The paragraphs required will depend on the payment terms for the client. Each client has a payment option from a drop down box (50% deposit and payment in full).

At the moment I have the drop down box choices as “50% deposit” or “payment in full” and associated descriptions containing the paragraphs. But I am struggling to find a way to insert the “descriptions” field (if it exists) into the Word document.